scholarly journals Effective and selective removal of phosphate from water by the Co(II)-based adsorbent

2019 ◽  
Vol 1 (1) ◽  
pp. 134-144 ◽  
Author(s):  
Keke Han ◽  
Deng You ◽  
Penghui Shao ◽  
Liming Yang ◽  
Hui Shi ◽  
...  
Keyword(s):  
Water Management ◽  
Valence Electron ◽  
Langmuir Model ◽  
Phosphate Removal ◽  
Coordination Mechanism ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Phosphate Ions ◽  
Competing Ions

Abstract In this study, a novel Co(II)-based adsorbent Co-H2L is developed for the removal of phosphate. The batch experiments demonstrate that the Co-H2L possesses preferable ability of phosphate capture from water in mildly acidic to neutral pHs, with a maximum adsorption capacity of 194.44 mg P g−1. Adsorption isotherms for phosphate agree with the Langmuir model, suggesting a monolayer process. The mechanism for phosphate adsorption onto Co-H2L mainly followed the coordination mechanism, and the Co valence electron orbitals play the key role in the phosphate adsorption. In addition, the Co-H2L adsorbent can selectively remove phosphate ions in the presence of the competing ions (Cl−, NO3−, and SO42−) at higher concentrations. Our results therefore indicate that the Co(II)-based adsorbent is expected to find extensive applications in phosphate removal for water management.

scholarly journals Kinetic analysis of sucrose activated carbon for nutrient removal in water

2020 ◽  
Vol 3 (1) ◽  
pp. 208-220
Author(s):  
Sara Jamaliniya ◽  
O. D. Basu ◽  
Saumya Suresh ◽  
Eustina Musvoto ◽  
Alexis Mackintosh
Keyword(s):  
Activated Carbon ◽  
Kinetic Analysis ◽  
Adsorption Capacity ◽  
Nitrate Removal ◽  
Freundlich Isotherm ◽  
Langmuir Model ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Isotherm Models ◽  
Nitrate Adsorption

Abstract A renewable, green activated carbon made from sucrose (sugar) was compared with traditional bituminous coal-based granular activated carbon (GAC). Single and multi-component competitive adsorption of nitrate and phosphate from water was investigated. Langmuir and Freundlich isotherm models were fitted to data obtained from the nitrate and phosphate adsorption experiments. Nitrate adsorption fits closely to either Freundlich or Langmuir model for sucrose activated carbon (SAC) and GAC with a Langmuir adsorption capacity of 7.98 and 6.38 mg/g, respectively. However, phosphate adsorption on SAC and GAC demonstrated a selective fit with the Langmuir model with an adsorption capacity of 1.71 and 2.07 mg/g, respectively. Kinetic analysis demonstrated that adsorption of nitrate and phosphate follow pseudo-second-order kinetics with rate constant values of 0.061 and 0.063 g/(mg h), respectively. Competitive studies between nitrate and phosphate were demonstrated in preferential nitrate removal with GAC and preferential phosphate removal with SAC. Furthermore, nitrate and phosphate removals decreased from 75% removal to 35% removal when subject to multi-component solutions, which highlights the need for adsorption analysis in complex systems. Overall, SAC proved to be competitive with GAC in the removal of inorganic contaminants and may represent a green alternative to coal-based activated carbon.

Reduction of highly concentrated phosphate from aqueous solution using pectin-nanoscale zerovalent iron (PNZVI)

2016 ◽  
Vol 73 (11) ◽  
pp. 2689-2696 ◽  
Author(s):  
Hongyu Wang ◽  
Zhuocheng Zou ◽  
Xuelian Xiao ◽  
Dan Chen ◽  
Kai Yang
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Phosphate Removal ◽  
Zerovalent Iron ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Surface Areas ◽  
Nanoscale Zerovalent Iron ◽  
The Fourier Transform

Pectin-nanoscale zerovalent iron (PNZVI) has been studied as an effective phosphate adsorption material to remove highly concentrated phosphate from aqueous solution. Batch phosphate removal and equilibrium experiments were conducted in order to evaluate the effects of environmental factors such as pH, coexisting anions and ionic strengths on phosphate removal by PNZVI. The scanning electron microscope images of nanoscale zerovalent iron (NZVI) and PNZVI demonstrated that PNZVI exhibited larger specific surface areas than NZVI so that PNZVI had higher phosphate removal efficiency than NZVI. Equilibrium experiments showed that phosphate adsorption by PNZVI was well fitted with the Freundlich and Langmuir models. In addition, the maximum adsorption capacity reached 277.38 mgP/gPNZVI. The ionic strengths and common anions showed no significant effects on the process of phosphate adsorption by PNZVI. The phosphate removal efficiency increased to a peak value with pH increased from 2.0 to 5.0, then decreased with pH further increased from 5.0 to 10.0. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses of PNZVI and P-loaded PNZVI indicated that adsorption, rather than redox reaction, was the dominant mechanism for the removal of phosphate by PNZVI.

La2O3-modified MCM-41 for efficient phosphate removal synthesized using natural diatomite as precursor

2019 ◽  
Vol 79 (10) ◽  
pp. 1878-1886 ◽  
Author(s):  
Xiaoning Jia ◽  
Xiaojuan He ◽  
Kaixuan Han ◽  
Yuhong Ba ◽  
Xia Zhao ◽  
...  
Keyword(s):  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Treated Wastewater ◽  
Molar Ratio ◽  
Phosphate Adsorption ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Isothermal Model ◽  
Enhanced Adsorption ◽  
Ph Range

Abstract In this study, an ordered mesoporous silica modified with lanthanum oxide was synthesized using diatomite as silica source and applied for adsorption of phosphate from aqueous solution. By taking cost-effectiveness for practical application into consideration, the adsorbent with a theoretical La/SiO2 molar ratio of 0.2 (La0.2M41) possessed a promising performance. In the batch adsorption tests, the adsorbents with La2O3 loading possessed markedly enhanced adsorption capacities. Phosphate uptake by La0.2M41 was pH-dependent with the highest sorption capacities observed over a pH range of 3.0–6.0. Coexistent anions displayed an adverse effect on phosphate adsorption following the order of CO32−  > F−  > NO3− > Cl− > SO42−. In the kinetic study, phosphate adsorption onto La0.2M41 followed the pseudo-second-order equation better than the pseudo-first-order, suggesting chemisorption. The Langmuir isothermal model well described the adsorption isotherm data, showing a maximum adsorption capacity for phosphate of up to 263.16 mg/g at 298 K. In a real treated wastewater effluent with phosphate concentration of 2.5 mg P/L, La0.2M41 efficiently reduced the phosphate concentration to 28 µg P/L.

One-Pot Synthesis of Mesoporous MCM-41 with Different Functionalization Levels and their Adsorption Abilities to Phosphate

2012 ◽  
Vol 476-478 ◽  
pp. 1969-1973 ◽  
Author(s):  
Wei Ya Huang ◽  
Jun Yang ◽  
Yuan Ming Zhang
Keyword(s):  
Removal Rate ◽  
Langmuir Model ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Experiment Data ◽  
Sorption Equilibrium ◽  
One Pot ◽  
Adsorption Capacities ◽  
Mcm 41

Ethylenediamine (EDA) functionalized mesoporous MCM-41 particles displaying various functionalization levels have been prepared by one-pot method. The prepared samples were treated with Fe(III) to form cationic complexes inside MCM-41 pores (MCM-41-NN-Fe-x%, x=10, 20 and 30) for trapping phosphate from water. The prepared adsorbents were characterized by XRD, BET, TGA and elemental analysis, and their phosphate adsorption performances were studied. The results showed that the phosphate removal rate of all the prepared adsorbents were higher than 95% at the initial phosphate concentration of 2 ppm. Additionally, the Langmuir model was used to simulate the sorption equilibrium, and the results indicated that the experiment data agreed well with the Langmuir model. The maximum adsorption capacities calculated from the Langmuir model increased with the increase of diamino loadings in adsorbents, and the maximum adsorption capacities of MCM-41-NN-Fe-30% was 52.5 mg/g.

scholarly journals Kinetic and Thermodynamic Studies on the Phosphate Adsorption Removal by Dolomite Mineral

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoli Yuan ◽  
Wentang Xia ◽  
Juan An ◽  
Jianguo Yin ◽  
Xuejiao Zhou ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Removal Rate ◽  
Second Order ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Thermodynamic Studies ◽  
Pseudo Second Order ◽  
Second Order Model

The efficiency of dolomite to remove phosphate from aqueous solutions was investigated. The experimental results showed that the removal of phosphate by dolomite was rapid (the removal rate over 95% in 60 min) when the initial phosphate concentration is at the range of 10–50 mg/L. Several kinetic models including intraparticle diffusion model, pseudo-first-order model, Elovich model, and pseudo-second-order model were employed to evaluate the kinetics data of phosphate adsorption onto dolomite and pseudo-second-order model was recommended to describe the adsorption kinetics characteristics. Further analysis of the adsorption kinetics indicated that the phosphate removal process was mainly controlled by chemical bonding or chemisorption. Moreover, both Freundlich and Langmuir adsorption isotherms were used to evaluate the experimental data. The results indicated that Langmuir isotherm was more suitable to describe the adsorption characteristics of dolomite. Maximum adsorption capacity of phosphate by dolomite was found to be 4.76 mg phosphorous/g dolomite. Thermodynamic studies showed that phosphate adsorption was exothermic. The study implies that dolomite is an excellent low cost material for phosphate removal in wastewater treatment process.

scholarly journals Equilibrium isotherm studies of copper and zinc removal from model solutions using natural and alkaline treated hornbeam sawdust

2020 ◽  
Vol 15 (2) ◽  
pp. 37-47
Author(s):  
Zdenka Kováčová ◽  
Štefan Demčák ◽  
Magdaléna Bálintová
Keyword(s):  
Adsorption Capacity ◽  
Langmuir Model ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Zinc Removal ◽  
Equilibrium Data ◽  
Copper Zinc ◽  
The Fourier Transform

AbstractIn the present study, sawdust an industrial by-product available in large quantities as sorbent material was studied. The removal adsorption capacity of Cu(II) and Zn(II) from aquatic solutions was obtained. The batch experiments were carried out to determine the effect of initial concentration of copper/zinc solution at pH=4.0 onto natural hornbeam and hornbeam modified with NaOH and KOH. The Fourier transform infrared spectroscopy (FTIR) determined the changes in functional groups after the modification of sawdust. The equilibrium data were fitted with four isotherm models - Langmuir, Freundlich, Tempkin and Dubinin– Radushkevich. The Langmuir model was found to be most suitable and the maximum adsorption capacity obtained for modified hornbeam sawdust was 2 to 4-times higher as in natural one for both heavy metals.

scholarly journals Enhanced Phosphate Removal from Water by Honeycomb-Like Microporous Lanthanum-Chitosan Magnetic Spheres

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1659 ◽  
Author(s):  
Rong Cheng ◽  
Liang-Jie Shen ◽  
Ying-Ying Zhang ◽  
Dan-Yang Dai ◽  
Xiang Zheng ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Active Sites ◽  
Lanthanum Oxide ◽  
Ph Value ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Magnetic Spheres ◽  
Hierarchical Porous

The removal of phosphate in water is crucial and effective for control of eutrophication, and adsorption is one of the most effective treatment processes. In this study, microporous lanthanum-chitosan magnetic spheres were successfully synthetized and used for the removal of phosphate in water. The characterization results show that the dispersion of lanthanum oxide is improved because of the porous properties of the magnetic spheres. Moreover, the contact area and active sites between lanthanum oxide and phosphate were increased due to the presence of many honeycomb channels inside the magnetic spheres. In addition, the maximum adsorption capacity of the Langmuir model was 27.78 mg P·g−1; and the adsorption kinetics were in good agreement with the pseudo-second-order kinetic equation and intra-particle diffusion model. From the results of thermodynamic analysis, the phosphate adsorption process of lanthanum-chitosan magnetic spheres was spontaneous and exothermic in nature. In conditional tests, the optimal ratio of lanthanum/chitosan was 1.0 mmol/g. The adsorption capacity of as-prepared materials increased with the augmentation of the dosage of the adsorbent and the decline of pH value. The co-existing anions, Cl− and NO3− had little effect on adsorption capacity to phosphate, while CO32− exhibited an obviously negative influence on the adsorption capacity of this adsorbent. In general, owing to their unique hierarchical porous structures, high-adsorption capacity and low cost, lanthanum-chitosan magnetic spheres are potentially applicable in eutrophic water treatment.

scholarly journals Adsorption of glyphosate in chilean soils and its relationship with unoccupied phosphate binding sites

2003 ◽  
Vol 38 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Marcelo Kogan ◽  
Alejandra Metz ◽  
Rodrigo Ortega
Keyword(s):  
Adsorption Capacity ◽  
Binding Sites ◽  
Hplc Method ◽  
Langmuir Model ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Phosphate Binding ◽  
Uv Detector ◽  
Linear Behavior ◽  
Exchangeable Al

The objective of this work was to investigate glyphosate adsorption by soils and its relationship with unoccupied binding sites for phosphate adsorption. Soil samples of three Chilean soils series - Valdivia (Andisol), Clarillo (Inceptisol) and Chicureo (Vertisol) - were incubated with different herbicide concentrations. Glyphosate remaining in solution was determined by adjusting a HPLC method with a UV detector. Experimental maximum adsorption capacity were 15,000, 14,300 and 4,700 mg g¹ for Valdivia, Clarillo, and Chicureo soils, respectively. Linear, Freundlich, and Langmuir models were used to describe glyphosate adsorption. Isotherms describing glyphosate adsorption differed among soils. Maximum adjusted adsorption capacity with the Langmuir model was 231,884, 17,874 and 5,670 mg g-1 for Valdivia, Clarillo, and Chicureo soils, respectively. Glyphosate adsorption on the Valdivia soil showed a linear behavior at the range of concentrations used and none of the adjusted models became asymptotic. The high glyphosate adsorption capacity of the Valdivia soil was probably a result of its high exchangeable Al, extractable Fe, and alophan and imogolite clay type. Adsorption was very much related to phosphate dynamics in the Valdivia soil, which showed the larger unoccupied phosphate binding sites. However relationship between unoccupied phosphate binding sites and glyphosate adsorption in the other two soils (Clarillo and Chicureo) was not clear.

Adsorption of Phosphate onto Slag from Aqueous Solution

2012 ◽  
Vol 550-553 ◽  
pp. 2255-2258
Author(s):  
Bing Bing Liu ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Langmuir Model ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
High Adsorption ◽  
Pseudo Second Order

Phosphate adsorption from aqueous solution using slag was investigated as the function of pH, contact time and adsorbent dosage. The results showed that the optimum value of pH was 2. Both Langmuir isotherm and Freundlich isotherm model were fit to describe the phosphate adsorption, and the maximum adsorption capacity from Langmuir model calculated was 9.09 mg/L. The adsorption process on slag followed pseudo second-order kinetic. Due to the relatively high adsorption capacity, the slag has the potential for application to removal phosphate from wastewater.

scholarly journals Bentonite surface modification and characterization for high selective phosphate adsorption from aqueous media and its application for wastewater treatments

2016 ◽  
Vol 7 (2) ◽  
pp. 175-186 ◽  
Author(s):  
S. Yaghoobi-Rahni ◽  
B. Rezaei ◽  
N. Mirghaffari
Keyword(s):  
Adsorption Capacity ◽  
Aqueous Media ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Modified Bentonite ◽  
X Ray ◽  
Langmuir Isotherm Model ◽  
Better Than

Raw and modified bentonite has been used to develop effective sorbents to remove phosphate from aqueous solution. Acid thermoactivation, Rewoquate, Irasoft, calcium, Fe and Al were employed to treat the bentonite. Results show that samples adsorption capacity for phosphate is in the order of, unmodified bentonite = acid thermoactivation < Rewoquate < calcium ≅ Irasoft < Fe < Al ≅ Fe-Al. The phosphate adsorption with Fe-Al-bentonite (FAB) modification was more than 99% and the phosphate removal reached the peak value in the initial 30 min. The phosphate adsorption of FAB was pH independent in the range of 2–10. The common coexisting ions in wastewater have no effect on the phosphate adsorption. The phosphate adsorption results were very well fitted in the Freundlich and Langmuir isotherm model and the maximum adsorption capacity was 8.33 mg P/g at pH 6.5 for 1 hour, which was better than similar modified bentonite with low time and Fe-Al consumption. FAB was characterized by scanning electron microscopy, X-ray diffraction, X-ray fluorescence and Fourier transform infrared. Therefore, the results confirm that FAB is a selective phosphate sorbent and environmentally friendly for its potential application for phosphate removal from wastewater.

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